ELECTROCHEMICAL OXYGEN REDUCTION CATALYST

Provided is an electrochemical oxygen reduction catalyst comprising platinum-containing nanoparticles and at least one member selected from the group consisting of a specific polymer containing a melamine compound as a monomer and a specific melamine compound, the electrochemical oxygen reduction catalyst having not only high oxygen reduction activity (low overvoltage), but also high durability at 70 to 85° C., which are practical temperature conditions.